Fold public-acme into route-proxy; drop dhcpcd and cloudflare-dns (hq ADR 0226)

public-acme ran nothing and had one consumer. The proxy now states the issuer itself, byte for byte
what the binding rendered, so its account directory and every certificate stay put. dhcpcd and
cloudflare-dns are assigned nowhere and nothing requires what they provide.

modules/route-proxy/module.json

@@ -19,11 +19,9 @@
     "route": "${dir:routes-dir}/mesh.json"
   },
   "requires": [
-    "acme-ca",
     "internal-acme-ca"
   ],
   "binds": {
-    "acme-ca": "${dir:state}/acme-ca.json",
     "internal-acme-ca": "${dir:state}/internal-acme-ca.json"
   },
   "own-secrets": {
@@ -81,7 +79,7 @@
       "type": "file",
       "path": "${dir:state}/acme.env",
       "mode": "0600",
-      "content": "ACME_DIRECTORY=https://${bound:acme-ca:at}:${bound:acme-ca:port}${bound:acme-ca:path}\nACME_ROOTS=https://${bound:acme-ca:at}:${bound:acme-ca:port}${bound:acme-ca:roots}\nACME_ROOTS_PATH=${bound:acme-ca:roots}\n"
+      "content": "ACME_DIRECTORY=https://acme-v02.api.letsencrypt.org:443/directory\nACME_ROOTS=https://acme-v02.api.letsencrypt.org:443\nACME_ROOTS_PATH=\n"
     },
     {
       "id": "internal-acme-env",